Aircraft passenger seat

ABSTRACT

An aircraft passenger seat comprises a primary seat ( 1 ) having a seat back ( 3 ) and a seat pan ( 4 ), and a secondary support surface ( 5 ) located or locatable opposite the primary, seat ( 1 ), the passenger seat being able to adopt each of an upright configuration, a reclined configuration and a substantially flat configuration, such that in the reclined configuration, the primary seat ( 1 ) is reclined relative to the upright configuration and the secondary support surface ( 5 ) is angled upwardly towards the primary seat ( 1 ) so as to support the lower leg(s) of a passenger seated in the primary seat ( 1 ); and in the substantially flat configuration, the secondary support surface ( 5 ) is substantially horizontal and the seat back ( 3 ), the seat pan ( 4 ) and the secondary support surface ( 5 ) form a substantially flat and continuous surface wherein the secondary support surface ( 5 ) is rotatable about an axis between the reclined and substantially flat configurations, said axis being translated between the reclined and substantially flat configurations.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/557,096, filed on Jul. 24, 2012, which is a continuation of U.S.application Ser. No. 12/158,637, filed on Feb. 23, 2009, abandoned, eachof which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an aircraft passenger seat,particularly but not exclusively to an aircraft sleeper seat convertibleinto a substantially flat bed.

2. Background Art

Examples of prior art aircraft sleeper seats are disclosed in theapplicant's patent publications WO 96/18537 and WO00/21831, embodimentsof which include the current British Airways First and Club World seatsrespectively. Both of these seats can be converted into a flat,horizontal bed, and have enjoyed great commercial success. However,there is intense competition to provide ever-greater comfort and spacefor aircraft passengers.

Passenger seats for aircraft are subject to stringent designconstraints, many of which are not applicable to seats for other vehicletypes. One problem is the need to meet the relevant safety standards foraircraft passenger seats, such as the 16 g test that requires seats tosurvive deceleration of 16 g in a takeoff/landing position. Anotherproblem is the need to minimize the weight of the seat, since carryingextra weight on an aircraft increases fuel consumption and thereforemonetary and environmental cost. Hence, the seat must be both strong andlight.

Another problem relates to the use of space. Any given aircraft has amaximum area for passenger seating, which must be used in the mostspace-efficient manner possible so as to maximize the seating area andlegroom available to each passenger, while allowing unimpeded exit fromthe seat. It is also important for cost reasons to fit as many passengerseats as possible in the available area.

Another problem relates to the level of comfort of the seat. Aircraftpassenger seats may be used for day flights, in which the passenger willwant to work, eat and/or relax, and night flights during which thepassenger will want to sleep. Preferably, an aircraft passenger seatshould be able to adopt comfortable positions for all of theseactivities, yet also be able to meet the relevant safety standards in atakeoff/landing position.

Another problem relates to the psychological and/or social needs ofaircraft passengers, who may desire privacy while working, eating orsleeping, or may wish to interact with a travelling companion. There arealso some arrangements that are undesirable for aesthetic and/orpsychological reasons; for example, it is preferred that parts of theseat mechanism are not visible to the passenger.

Patent publication EP-A-1 116 654 (BE Aerospace) discloses an aircraftpassenger sleeper seat that can adopt fully upright, semi-reclined orlounge and fully reclined or sleep positions. The seat includes anottoman that functions as a foot or leg support, and has a top cushionand a pivoting legrest cushion.

U.S. Pat. No. 2,583,223 (Mayer) discloses a foot and leg rest forpassenger vehicles, having a rearwardly inclined foot rest position andan elevated, forwardly inclined leg rest position.

Patent publication WO 98/36967 (Singapore Airlines) discloses anaircraft passenger seat with armrests that are lowered as the seatreclines, so as to lie flush with a seat portion in a fully reclinedposition and thereby improve the width available to the passenger.

U.S. Pat. No. 6,692,069 (Beroth et. al.) discloses an aircraft passengersleeper seat in which an armrest pivots forwards as the seat reclines,so as to be aligned with a seat bottom in a fully reclined position andthereby improve the width available to the passenger. However, thisarrangement does not allow the sleeping surface to be horizontal.

Statements of the Invention

According to a first aspect of the invention, there is provided anaircraft passenger seating arrangement comprising a primary seat havinga seat pan and a seat back, and a secondary surface positionableopposite and separate from the primary seat, the passenger seatingarrangement being able to adopt a first, substantially uprightconfiguration in which the seat back is substantially vertical, asecond, semi-reclined configuration in which the seat back is reclinedbetween the horizontal and the vertical and a third, fully reclinedconfiguration in which the seat back and seat pan are substantiallyhorizontal, wherein in the second configuration the secondary surface isangled upwardly to support the lower leg(s) of the passenger and in thethird configuration, the secondary surface is substantially horizontaland provides a substantially flat, continuous sleeping surface with theseat pan and the seat back.

An advantage of this seating arrangement is that configurations suitablefor sitting upright, reclining and sleeping can be provided. Hence, theseating arrangement may be comfortable for long periods during day ornight flights. In the second, semi-reclined position the lower leg(s) ofthe passenger may be fully supported, thereby providing a comfortablereclining position without the need for a footrest. Another advantage isthat these configurations may be provided by means of only three supportsurfaces (the seat back, seat pan and secondary surface), allowing asimple mechanism for moving the support surfaces into the differentconfigurations.

Preferably, in the first configuration, the secondary surface issubstantially horizontal and is displaced both downwards andhorizontally towards the primary seat, relative to the thirdconfiguration, so as to provide a footrest. An advantage of thisarrangement is that the secondary surface is able to act both as a legrest, in the second and third configurations, and as a foot rest, in thefirst configuration

Preferably, the secondary surface is pivotable to a substantiallyvertical, stowed position. An advantage of this arrangement is that thesecond surface may provide minimal obstruction to a passenger leavingthe primary seat. The secondary surface may be pivoted upwardly to thesubstantially vertical position, which is advantageous in that it allowsa comparatively long secondary surface and a comparatively shortmechanism for the secondary surface. Advantageously, the secondarysurface may be stowed up against a housing, such as that of a seatingarrangement of another passenger. Part of the mechanism of the secondaryseat may be housed within that housing.

The secondary surface is considered to be independently inventive andtherefore, according to a second aspect of the invention, there isprovided a foot/legrest for an aircraft passenger seat, the foot/legresthaving a support surface and a mechanism for securing the supportsurface in a first, substantially horizontal position and a secondposition at a substantial angle to the horizontal and verticaldirections, for supporting the lower leg(s) of a passenger seated in theseat in a semi-reclined position, wherein the mechanism is arranged torotate and translate the support surface between the first and secondpositions. The mechanism may include a pivot about which the supportsurface is rotatable, and means for translating the pivot. Preferably,the translating means is arranged to translate the pivot with a verticalcomponent, and most preferably to translate the pivot in a direction atan angle substantially intermediate between the horizontal and verticaldirections.

Preferably, the mechanism is also able to secure the support surface ina third, substantially horizontal position displaced in a verticaldirection from the first position. Preferably, the third position isalso displaced in a horizontal direction from the first position. Anadvantage of this arrangement is that the support surface may act as aleg rest for the passenger both in a semi-reclined and a sleepingposition, while also acting as a foot rest for the passenger in anupright sitting position.

Preferably, the mechanism is operable to move the support surface to asubstantially vertical, stowed position. An advantage of thisarrangement is that the support surface then provides minimalobstruction to the passenger.

Preferably, the mechanism is arranged to secure the support surface suchthat the support surface is able to move downwardly if a force or torquegreater than a predetermined threshold is applied downwardly to thesupport surface, and the support surface is able subsequently to returnto its secured position; in other words, the mechanism gives way but isnot damaged. An advantage of this arrangement is that, when stepped onor sat upon, the support surface at least partially moves out of the wayof the passenger.

According to another aspect of the present invention, there is providedan aircraft passenger seat comprising a seat back, a seat pan and aframe, the seat being positionable in each of an upright configuration,a reclined configuration in which the seat back is reclined relative tothe upright configuration and a substantially flat configuration inwhich the seat back and the seat pan form a substantially flat andcontinuous surface, wherein the seat back is guided so as to recline asthe seat back moves forward relative to the frame, the seat back beingconnected to the seat pan by a pivotal connection between the seat backand the seat pan; and by a torque transmitting mechanism for governingthe angle between the seat back and the seat pan as the seat backreclines. The seat back and/or the seat pan may be guided at least inpart by engagement with the frame, for example by a pin guided along atrack. The torque transmitting mechanism may comprise a cam mechanismseparate from, and moveable relative to the frame.

According to another aspect of the present invention, there is providedan aircraft passenger seat comprising a seat back and a seat pan, theseat being positionable in each of an upright configuration and asubstantially flat configuration in which the seat back and the seat panform a substantially flat and continuous surface, the seat having aretractable armrest having a raised position in which the retractablearmrest overhangs the seat pan in the upright configuration and alowered position in which at least part of the armrest is located on orimmediately above the seat back in the substantially flat configuration.

According to another aspect of the present invention, there is providedan aircraft passenger seat having a housing separating the seat from anadjacent aircraft passenger seat, the housing including a screenarranged to retract automatically in response to an electrical signal.The screen may be latched in a deployed position, and the latch releasedin response to the electrical signal. The screen may be latched by anelectrical latch, and the electrical signal may comprise a reduction orremoval of electrical power to the electrical latch.

According to another aspect of the present invention, there is providedan aircraft passenger seat having a screen between the seat and anadjacent aircraft passenger seat, the screen having a transparencydependent on vertical viewing angle, such that the screen is nottransparent at a low vertical viewing angle but is transparent at a highvertical viewing angle.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to thedrawings identified below.

FIG. 1a is a perspective view of a seating arrangement in an embodimentof the invention, in a first configuration suitable for sittingsubstantially upright.

FIG. 1b is a perspective view of the seating arrangement in a secondconfiguration, suitable for takeoff and/or landing.

FIG. 1c is a perspective view of the seating arrangement in a thirdconfiguration, suitable for resting.

FIG. 1d is a perspective view of the seating arrangement in a fourthconfiguration, suitable for sleeping.

FIG. 2a is a schematic side view of a seating arrangement in anembodiment of the invention, in the first configuration suitable forsitting substantially upright.

FIG. 2b is a schematic side view of the seating arrangement in thesecond configuration, suitable for takeoff and/or landing.

FIG. 2c is a schematic side view of the seating arrangement in the thirdconfiguration, suitable for resting.

FIG. 2d is a schematic side view of the seating arrangement in thefourth configuration, suitable for sleeping.

FIG. 3a is a lateral cross-sectional view of a primary seat of theseating arrangement showing the configuration of armrests in a raisedposition.

FIG. 3b is a corresponding lateral cross-sectional view showing theconfiguration of armrests in a lowered position.

FIG. 4 is a side view of a reclining mechanism for the primary seat.

FIG. 4a shows a detail of the reclining mechanism of FIG. 4 in the firstconfiguration.

FIG. 4b shows a detail of the reclining mechanism of FIG. 4 in thesecond configuration.

FIG. 4c shows a detail of the reclining mechanism of Figure of 4 in thethird configuration.

FIG. 4d shows a detail of the reclining mechanism of Figure of 4 in thefourth configuration.

FIG. 5 is a perspective view of the reclining mechanism.

FIG. 6a is a detailed view of the reclining mechanism in the firstconfiguration.

FIG. 6b is a detailed view of the reclining mechanism in the secondconfiguration.

FIG. 6c is a detailed view of the reclining mechanism in the thirdconfiguration.

FIG. 6d is a detailed view of the reclining mechanism in the fourthconfiguration.

FIG. 7a is a detailed view of a first embodiment of the armrestmechanism in the raised position.

FIG. 7b is a detailed view of the first embodiment of the armrestmechanism in the lowered position.

FIG. 7c is a detailed view of a second embodiment of the armrestmechanism.

FIG. 7d is a close-up view of the lower surface of the arrest support inthe second embodiment.

FIG. 7e is a detailed view of a third embodiment of the armrestmechanism, in a raised position.

FIG. 7f is a detailed view of the third embodiment of the armrestmechanism, in a lowered position.

FIG. 7g is a detailed view of the third embodiment of the armrestmechanism, with the armrest lifted out of the lowered position.

FIG. 8 is a perspective view of the support mechanism of the secondarysupport.

FIG. 9 is a detailed perspective view of the support mechanism.

FIG. 10 is a detailed perspective view of a rack and pinion in thesupport mechanism.

FIG. 11 is a perspective view of the mounting of the support mechanismwithin the housing of a forwardly adjacent seat.

FIG. 12 is a plan view of a seat layout in the cabin of an aircraft.

FIG. 12a shows an oppositely facing pair of seats in the layout of FIG.12.

FIGS. 13a and 13b show a privacy screen in raised and loweredconfigurations respectively.

FIG. 13c show a securing mechanism of the privacy screen.

FIG. 14 is a diagram illustrating the dependence of the transparency ofthe privacy screen on vertical viewing angle.

DETAILED DESCRIPTION OF THE EMBODIMENTS Seating Configurations

In this section, ‘horizontal’ and ‘vertical’ are defined with referenceto the floor of the passenger seating area of the aircraft. As inwell-known in the art, the angle of the floor relative to thegravitational horizontal is determined by the pitch of the aircraft,which is about 15° during takeoff and landing, and about 3° in levelflight. When discussing an individual seat, ‘forward’ and ‘rearward’ aredefined with reference to the direction in which the passenger faceswhen seated.

FIGS. 1a to 1d show the same perspective view of a seating arrangementin an embodiment of the invention, in different configurations, whileFIGS. 2a to 2d show the arrangement in schematic lateral view, in therespective configurations. The seating arrangement comprises a primaryseat 1 and a secondary support 2 opposite the primary seat 1. Thesupport surfaces of the primary seat 1 comprise a seat back 3 and a seatpan 4, while the support surface of the secondary support 2 comprises afoot/legrest 5. Left and right arm rests 8 a, 8 b are disposed eitherside of the seat pan 4.

The seat back 3 and the seat pan 4 are moveable together betweenupright, takeoff/landing, reclined and horizontal configurations bymeans of a seat reclining mechanism, embodiments of which will bedescribed below. In the horizontal and reclined configurations, the armrests 8 a, 8 b drop from a raised to a lowered position, under thecontrol of the seat reclining mechanism.

The seat reclining mechanism is at least partially housed within ahousing 6, so that it does not present a trap hazard to passengers, andis preferably not visible to passengers in normal use. The seat back 3is substantially maintained within the housing 6 in each of theconfigurations, so that the seat back 3 does not impinge into spacereserved for other passengers, and also does not present a trap hazard.The housing 6 partially surrounds the passenger, which affords a degreeof privacy. A retractable privacy screen 50 is located in a side wall ofthe housing 6, separating the seat from an adjacent seat.

A storage drawer 23 is provided within the housing 6, located at floorlevel.

The secondary support 2 in this embodiment is configurable independentlyof the primary seat 1 and is not linked to the seat reclining mechanism.The secondary support 2 can be manually secured in differentconfigurations, as described below.

In the first configuration as shown in FIGS. 1a and 2a , the seat back 3is at its most upright position and the seat pan 4 is in its rearmostposition. The arm rests 8 a, 8 b are in a raised position. Thefoot/legrest 5 is in a low, horizontal position, in which configurationit acts as a footrest. The first configuration is suitable for sittingupright, for example while the passenger is working or eating. The seatpan 4 is at about 10° to the horizontal, while the seat back 3 isbetween about 15-20° to the vertical.

In the second configuration as shown in FIGS. 1b and 2b , the seat back3 is more reclined and the seat pan 4 has moved forward and is moreinclined relative to its position in the first configuration. The angleof reclining of the seat back 3 is about 25-30° to the vertical and theangle of inclination of the seat pan 4 is about 15-20° to thehorizontal. One advantage of this configuration is to avoid tipping thepassenger out of the primary seat 1 during takeoff, where the primaryseat 1 faces towards the rear of the aircraft. The primary seat 1 meetsthe required safety standards for takeoff and landing, such as the 16 gtest, in the second configuration.

In the third configuration as shown in FIGS. 1c and 2c , the seat back 3is reclined by a large angle, such as 40-70°, to the vertical, and theseat pan 4 has moved forward relative to its position in the secondconfiguration. Again, the angle of reclining of the seat back 3 and thecorresponding forward movement of the seat pan 4 may be varied undercontrol of the passenger, to provide the desired degree of reclining.The angle of the seat pan 4 remains substantially constant, about 17° tothe horizontal. The arm rests 8 a, 8 b have dropped into the loweredposition. The third configuration is suitable for resting and/orin-flight entertainment. The foot/legrest 5 may be configured as shownin an angled position, sloping upwards in the rearward direction byabout 15° to the horizontal, so as to support the lower leg(s) of thepassenger. In this way, the passenger is supported in a reclined sittingposition, with weight distributed across the seat back 3, seat pan 4 andfoot/legrest 5. This configuration corresponds to the position that therelaxed human body adopts in a weightless environment, and is verycomfortable. Moreover, passengers who are accustomed to sleeping ontheir back may find this configuration suitable for sleeping. As aresult of the Z-shaped configuration of the seat back 3, seat pan 4 andfoot/legrest 5, the overall length that can be supported in the thirdconfiguration is greater than that supported in the fourth, flat andhorizontal configuration, so that unusually tall passengers may alsofind the third configuration suitable for sleeping. In one specificembodiment, the overall length supported in the third configuration is198 cm (78 inches), while an overall length of 183 cm (72 inches) issupported in the fourth configuration.

In the fourth configuration as shown in FIGS. 1d and 2d , the seat back3 and the seat pan 4 are substantially horizontal and form asubstantially continuous, flat surface. The arm rests 8 a, 8 b arelowered, and rest adjacent to the seat back 3. The foot/legrest 5 may beconfigured as shown in a high horizontal position, raised and movedforwardly relative to the second configuration. In this position, thefoot/legrest 5 forms a substantially flat, continuous surface with theseat back 3 and the seat pan 4. The fourth configuration is suitable forsleeping, and preferably provides sufficient width to allow passengersto sleep on their sides, back or front.

Arm Rests

The configuration of the arm rests 8 a, 8 b enhances the width availableto the passenger both when sitting, in the first and secondconfigurations, and resting, as in the third and fourth configurations.The configuration of the arm rests 8 a, 8 b in the raised position isshown in lateral cross-section in FIG. 3a . The armrests 8 a, 8 b aresupported on relatively thin, elongate movable armrest supports 9 a, 9 bthat project from the housing 6. At least the inner edges of thearmrests 8 a, 8 b project inwardly so as to overhang the seat pan 4.This arrangement provides a width W1 for the passenger's hips under thearmrests 8 a, 8 b greater than the distance D between the armrests 8 a,8 b.

The configuration of the arm rests 8 a, 8 b in the lowered position isshown in lateral cross-section in FIG. 3b . The armrest supports 9 a, 9b have retracted into the housing 6 and the armrests 8 a, 8 a partiallyrest on or just above the seat back 3. The upper surfaces of the armrests 8 a, 8 a are not coplanar with the upper surface of the seat back3, but are nevertheless sufficiently adjacent to allow part of thepassenger's body, such as the elbow or shoulder, to rest comfortably onthe arm rests 8 a, 8 b when the passenger is resting. Thus, the width ofthe armrests 8 a, 8 b forms part of the available width W2 of thesleeping surface. In a specific embodiment, in which the width W3 of theseat back 3 and seat pan 4 is 53 cm (21 inches), the width W2 of thesleeping surface at the shoulder position of a passenger is 66 cm (26inches).

Primary Seat Mechanism

As described above, the mechanism for reclining the primary seat 1 isrequired to move the seat back 3 and the seat pan 4 through a complexpath as they pass from the first to the fourth configuration. Inparticular, the seat pan 4 is required to move from a slightlyrearwardly inclined position (i.e. with the forward end higher than therearward end) in the first configuration, to a more rearwardly inclinedposition in the second and third configurations, to a horizontalposition in the fourth configuration. In other words, the seat pan 4first increases and then decreases its inclination as the seat back 3reclines. The top of the seat back 3 moves substantially verticallydownwards as the seat back 3 reclines, while the bottom of the seat back3 moves forwards and remains adjacent to the rearward end of the seatpan 4. These requirements must be met with the least possible weight andthe sufficient strength to pass the relevant safety standards. Amechanism suitable for meeting these requirements will now be disclosedwith reference to FIGS. 4, 4 a and 5 show respectively side andperspective views of the principal parts of the support and recliningmechanism of the primary seat 1. A lower frame 10 is arranged to befixed to the floor of the passenger compartment by a suitable fixingarrangement. An upper frame 11, fixed to the lower frame 10, includes anarcuate guide track 12. The seat back 3 and seat pan 4 are supported ona carriage comprising a drive rail 13, a seat pan support 14, the seatpan 4, the seat back 3, and a linkage between the seat back 3 and theseat pan comprising a torque member 15 and a cam 16.

The drive rail 13 is reciprocally drivable in the horizontal directionby a motor and drive train (not shown). For example, the underside ofthe drive rail 13 may comprise a rack driven by a pinion mounted on theupper frame 11. The seat pan support 14 is mounted on the forward end ofthe drive rail 13, and is pivotally connected to the forward end of theseat pan 4 at pivot P0.

The seat back 3 includes a forward roller 17 and a rearward roller 18,which are arranged to move along the guide track 12 while supporting theseat back 3, thus controlling the inclination of the seat back 3 as itreclines and the rollers 17, 18 move forwards along the guide track 12.

The seat back 3 is pivotally connected to the seat pan 4 at first pivotP1, and via the torque member 15 which is connected to the seat back 3at second pivot P2, coaxial with the forward roller 17, and at thirdpivot P3 under the rearward end of the seat pan 4. Note that the thirdpivot P3 and connecting parts of the torque member 15 and seat pan 4 areconcealed behind the drive rail 13 in FIG. 4, but are shown in dottedoutline in FIG. 4 a.

The rotation of the torque member 15 is governed by a pin 19 locatedwithin a cam track 20 within the cam 16. As the seat back 3 reclinesbetween the second and third configurations, the pin 19 travels alongthe cam track 20 and the inclination of the seat pan 4 remainssubstantially constant. As the seat back 3 approaches the fourth,horizontal configuration, the pin 19 reaches the end of the cam track 20and the torque member 15 rotates clockwise, lifting the rearward end ofthe seat pan 4 up so that the seat pan 4 assumes the horizontalposition.

In the embodiment shown in FIGS. 6a to 6d , the seat back 3 includes asupport roller 21 that enters an open-ended support track 22 in theupper frame 11 as the seat back 3 approaches the horizontalconfiguration, so as to provide an additional support point for the seatback 3 in the horizontal position. Note that in FIGS. 6a to 6d , someparts of the mechanism are not shown so that the underlying mechanismcan be seen.

Also shown is the drawer 23 for the adjacent seat, that fits under thereclining mechanism. As is apparent from FIG. 4, no part of thereclining mechanism extends below the upper frame 11. Thus, the drawer23 does not obstruct the seat pan 4 or reclining mechanism, and can beleft pulled out when the seat is reclined.

Armrest Mechanism First Embodiment

FIGS. 7a and 7b show a first embodiment of the armrest mechanism in theraised and lowered positions respectively. In the raised position, thelower surface of the armrest support 9 a, 9 b rests on a pin 30,moveable reciprocally along a substantially vertical arcuate track 31 inthe upper frame 11 and connected by a first linkage 32 to a fixed firstpivot 33 located on the upper frame 11 forward of the armrest support 9a, 9 b, and connected by a second linkage 34 to a second pivot 35moveable reciprocally along a substantially horizontal arcuate track 36in the upper frame 11. As the second pivot 35 moves forward along thehorizontal arcuate track 36 from the position shown in FIG. 7a to thatshown in FIG. 7b , the pin 30 falls along the substantially verticalarcuate track 31 as the first and second linkages 32, 34 rotateclockwise, and the armrest support 9 a, 9 b falls under gravity,following the pin 30, until the armrest support 9 a, 9 b comes to reston stops 37. The lower surface of the armrest support 9 a, 9 b includesa recessed portion, such that the pin 30 does not contact the lowersurface in the lowered position.

The second pivot 35 is preferably connected so as to move with theprimary seat reclining mechanism, such that the second pivot 35 movesforward as the primary seat 1 reclines. The second pivot may engageprimary seat reclining mechanism, or may be biased so as to abut againstpart of the seat reclining mechanism. This has the effect of loweringthe armrests 8 a, 8 b as the primary seat 1 moves into the thirdconfiguration, as described above. An advantage of the armrest mechanismis that the armrests 8 a, 8 b are not driven into the lowered position,but fall as the pin 30 falls. Therefore, any object trapped under thearmrests 8 a, 8 b as they fall will be subjected only to the weight ofthe armrests 8 a, 8 b and armrest supports 9 a, 9 b, and not to thedriving force of the armrest mechanism. The object can easily bereleased by manually lifting the relevant armrest 8 a, 8 b, withoutapplying force to the armrest mechanism. In other words, the armrestsupport 9 a, 9 b is biased against, but not engaged by the armrestmechanism. This bias may be entirely due to the weight of the armrestsupport 9 a, 9 b and armrest 8 a, 8 b, or may be enhanced by biasingmeans such as a spring.

Armrest Mechanism Second Embodiment

A second embodiment of the armrest mechanism is shown in FIGS. 7c and 7d. Similar parts to the first embodiment carry the same referencenumerals. In this embodiment, the first linkage 32 is not present, andthe armrest mechanism has a single linkage 34, the lower end of whichcomprises the pivot 35 moveable reciprocally along the substantiallyhorizontal arcuate track 36 in the upper frame 11. The upper end of thesingle linkage 34 comprises the pin 30 which is moveable along thesubstantially vertical arcuate track 31.

As the seat is moved into an upright position, a lifter blade 38 fixedto the drive rail 13 abuts the pivot 35 and pushes it rearwardly alongthe substantially horizontal arcuate track 36 so that the pin 30 risesin the substantially vertical arcuate track 31 and pushes the lowersurface of the armrest support 9 a, 9 b into the raised position. As theseat reclines, the pivot 35 is biased against the lifter blade 38 andmoves forwards with the lifter blade 38, so that the armrest moves tothe lowered position. The bias may be gravitational (due to the weightof the armrest mechanism) or may be achieved by a spring or otherbiasing means.

In the second embodiment, the lower surface of the armrest support 9 a,9 b has a re-entrant form as shown in FIG. 7d . A hook-shaped portion 39engages the pin 30 when the armrest is in the raised position. As thepin 30 moves downwardly and forwardly in the substantially vertical (butslightly forwardly inclined) arcuate track 31, it moves out ofengagement with the hook-shaped portion 39. As a result, the armrest isdriven by the armrest mechanism at an initial lowering stage. This hasthe advantage of preventing the armrest support 9 a, 9 b from stickingin the raised position. However, the armrest falls under gravity duringa final lowering stage as in the first embodiment, thus avoidingtrapping objects under the armrest.

Armrest Mechanism Third Embodiment

FIGS. 7e and 7f show a third embodiment of the armrest mechanism in theraised and lowered positions respectively. Similar parts to the firstand second embodiments carry the same reference numerals and theirdescription will not be repeated except where necessary.

In common with the first embodiment, the armrest mechanism of the thirdembodiment comprises first and second linkages 32, 34, rather than thesingle linkage 34 of the second embodiment. The first and secondlinkages 32, 34 are biased towards a collapsed position as shown in FIG.7f , whereby the armrest support 9 b is biased into the loweredposition. In this example, the bias is applied by springs 32′, 34′connected between the upper frame 11 and the first and second linkages32, 34 respectively.

The armrest mechanism is moved from the lowered position to the raisedposition of FIG. 7a by lifter blade 38 (not shown) similar to that ofthe second embodiment, which abuts the second pivot 35 and moves italong the horizontal arcuate track 36, thus raising the pin 30 and thearmrest support 9 b.

Unlike in the first embodiment, the pin 30 is enclosed within anelongate track or slot 39′ in an end portion of the armrest support 9 b.Like the hook-shaped portion 39 of the second embodiment, the slot 39′allows the pin 30 to reciprocate horizontally as the pin 30 moves up anddown the substantially vertical arcuate track 31. However, the slot 39′does not allow the armrest support 9 b to be lifted away from the pin 30when the armrest mechanism is in its lowered position. Instead, as shownin FIG. 7g , lifting the armrest 9 b causes the armrest mechanism tomove out of the collapsed configuration of FIG. 7f , against the bias.The second pivot 35 moves along the horizontal arcuate track 36, out ofabutment with the lifter blade 38.

In this way, the armrest 8 b can be lifted to free an object trappedunderneath. The trapping force is only that caused by the bias of thearmrest mechanism and by the weight of the armrest, rather than theforce of the seat reclining mechanism, because the armrest mechanism isbiased against the seat reclining mechanism but is not engaged by it.

Secondary Support Mechanism

The secondary support 2 is required to adopt the following positions:

-   i) Vertically stowed, to minimize obstruction to the passenger when    leaving the primary seat 1, or during takeoff or landing;-   ii) Low horizontal, positioned rearward so as to act as a footstool    when the primary seat is in the first configuration;-   iii) Angled upwardly, with the end towards the primary seat raised,    so as to act as a legrest when the primary seat 1 is in the third    configuration; and-   iv) High horizontal, positioned forward so as the form part of a    flat, horizontal bed in alignment with the primary seat 1 in the    fourth configuration.

A mechanism for achieving these different positions is shown in FIGS. 8to 10. As shown in FIG. 8, the foot/legrest 5 is mounted on a support 40arranged to slide along a track 41, which is inclined at an anglesubstantially offset from the horizontal and from the vertical so thatthe foot/legrest moves forward as it moves up the track 41. The angle ofinclination may be in the range 20-40° from the vertical, preferablyabout 30° from the vertical. The support 40 engages a rack 43 extendingparallel to the track 41. The foot/legrest 5 is pivotally mounted on thesupport 40 by means of a locking pivot 44 which allows the foot/legrest5 to be supported in horizontal, and upwardly inclined positions, aswell as being pivoted upwardly into the vertically stowed position. Theengagement of the support 40 with the rack 43, and the locking pivot 44,are released by pulling a handle 45 located within a handgrip in thefoot/legrest 5.

FIG. 9 shows the support 40 in more detail, without the foot/legrest 5.The handle 45 (not shown in FIG. 9) is connected to a release member 46mounted within a pivoting connector 47, to which the foot/legrest 5 isattached. The release member 46 is connected to a pin 48 locatedretractably in a groove 49, so as to secure the pivoting connector 47 inan inclined position. When the handle 45 is pulled, the release member46 lifts the pin 48 out of the groove 49 and allows the pivotingconnector 47 to pivot to the horizontal position.

The locking pivot 44 is preferably arranged to unlock when a torquegreater than a predetermined threshold is applied, the threshold beingselected such that the foot/legrest 5 will pivot downwardly when stoodupon or sat on by a passenger, but will support the feet or legs of apassenger when used as a footrest and a legrest respectively. This isachieved by a pair of inwardly-biased washers 50, at either end of thelocking pivot 44, which releasably engage outward parts of the pivotingconnector 47 and prevent it from pivoting below the horizontal position.When sufficient force is applied to the locking pivot 44, the inwardbias of the washers 50 is overcome and they move outward, disengagingthe pivoting connector 47 and allowing it to pivot downwardly. When thepivoting connector 47 is returned to its horizontal position, thewashers 50 are biased back into engagement and once again prevent thepivoting connector 47 from pivoting below the horizontal position.

FIG. 10 shows in detail the mechanism for engaging the support 40 on therack 43. A pinion 42 runs along the rack 43, and includes a clutch 51connected to the release member 46 by a linkage (not shown), so that theclutch 51 is disengaged and the support 40 can be moved up or down thetrack 41 to the desired position when the handle 45 is pulled. When thehandle 45 is released, the clutch prevents the pinion 42 from rotatingand the support 40 is secured in position on the rack 43. The weight ofthe foot/legrest 5 is counterbalanced by a torsion spring 52 thatapplies a torque to the pinion 42. As shown in FIG. 11, the secondarysupport mechanism may be housed within the housing 6 of the immediatelyforward passenger seat, so that the mechanism is not visible topassengers and does not present a hazard to them. Where there is noforward passenger seat, the secondary support mechanism may be housed ina partition wall or a discrete housing.

Passenger Seating Layout

FIG. 12 show an example of a passenger seating layout comprising twelvepassenger seating arrangements, each comprising a primary seat 1 and asecondary support 2, arranged in oppositely-facing pairs, as shown inmore detail in FIG. 12a . In each pair, one seat faces approximatelyforwardly and the other faces approximately rearwardly in the aircraft,parallel to a longitudinal seat pair axis A_(P) which is at a slightangle, for example 2°, to the longitudinal axis of the aisle A_(A). Thelongitudinal axis A_(S) of each seat of a pair is substantially parallelto the longitudinal axis of the seat pair A_(P). This slight angleallows greater waist and shoulder width for each primary seat 1, given aminimum width for the aisle. The outer armrests 8 a extend substantiallyparallel to the aisle axis A_(A).

Privacy Screen

As can be seen from FIG. 11, a privacy screen 50 is provided betweeneach seat of a seat pair. The privacy screen 50 may be raised, as shownfor example in FIGS. 1a to 1d , to provide privacy between passengers indifferent seats of the seat pair, or retracted so as to allowinteraction between the passengers. As shown in FIGS. 13a and 13b , theprivacy screen 50 comprises a plurality of horizontal slats 51 a-51 dslidable vertically in a frame 52. Each slat engages the adjacentslat(s), either directly or via connecting portions housed within theframe 52, so that lifting the top slat 51 a lifts all of the slats 51a-51 d into the raised position.

As shown in FIG. 13c , the top slat 51 a is secured in its raisedposition by an electrically operable latch, in the form of anelectromagnet 53. The privacy screen 50 may be released manually bypushing the top slat 51 a downwards with sufficient force to overcomethe magnetic force of the electromagnet 53. The electromagnet 53 ispowered by the power supply to the seat. In an emergency, the powersupply to each seat may be disconnected momentarily, such that theprivacy screen 50 automatically drops into its retracted position undergravity. This allows the passenger to reach an oxygen mask thatautomatically drops from a ceiling compartment. Since the ceilingcompartment may not be directly above some of the seats, it isadvantageous to allow passengers to reach over the privacy screen 50 inan emergency.

The privacy screen 50 may include a switch, located in or adjacent tothe frame, that locally disconnects the power to the electromagnet 53and allows the privacy screen 50 to be lowered without applying adownward force, as well as allowing the automatic dropping of theprivacy screen 50 to be tested. The switch may be located where it canbe conveniently actuated by cabin crew.

The slats 51 are preferably made from a translucent material, so thatnatural light from cabin windows can pass through the privacy screen 50.Most preferably, as shown in FIG. 14, the slats 51 are transparent whenviewed at a predetermined range of angles α-β relative to the horizontalplane, but are otherwise translucent, or opaque. The angles α and β areselected so that a member of cabin crew CC is able to see downwardlythrough the privacy screen 50 when raised, to determine whether apassenger's seatbelt is correctly fastened, but adjacent passengers P1,P2 cannot see each other when both seated. Thus, the material may have avertical transparency angle range of about 10° to 70°, preferably 25° to55°. Preferably, the transparency is substantially independent ofhorizontal viewing angle, but in an alternative embodiment the screen 50may be translucent when viewed at a high horizontal angle, such as 50°or greater, in one embodiment, the slats 51 are of transparent plasticcovered with a film of directionally transparent material, such ascurrently sold under the brand name Lumisty™ of Sumitomo Chemical Co.Ltd.

Alternative Embodiments

The above embodiments illustrate, but do not limit, the presentinvention. Alternative embodiments which may occur to the skilled readeron reading the above description may also fall within the scope of theinvention.

The invention claimed is:
 1. An aircraft passenger seat having a housingassociated with the seat that at least partially surrounds the seat, thehousing having a privacy screen arranged to retract automatically underthe force of gravity in response to disconnection or reduction ofelectrical power to the seat.
 2. The seat of claim 1, wherein theprivacy screen is biased towards a retracted position thereof, the seatincluding a latch for latching the privacy screen in a deployed positionthereof.
 3. The seat of claim 2, wherein the latch is electricallyenergized and arranged to release the screen when electrical power tothe latch is disconnected or reduced.
 4. The seat of claim 3, whereinthe latch comprises an electromagnet powered by the electrical power tothe seat.
 5. The seat of claim 3, including a switch arranged to locallydisconnect the electrical power to the latch so as to allow the screento retract.
 6. The seat of claim 1, wherein the screen comprises aplurality of substantially horizontal slats slidable in a substantiallyvertical direction between a deployed position and a retracted position.7. The seat of claim 6, wherein each said slat directly or indirectlyengages an adjacent one of said slats, such that the screen is moveablefrom the retracted position to the deployed position by raising an upperone of the slats.
 8. The seat of claim 6, wherein the screen is moveablefrom the deployed position to the retracted position by releasing anupper one of the slats.
 9. The seat of claim 1, wherein the screen has atransparency dependent on vertical viewing angle, such that the screenis not transparent at a low vertical viewing angle but is transparent ata high vertical viewing angle.
 10. The seat of claim 9, wherein thescreen is translucent or opaque at said low viewing angle.
 11. The seatof claim 9, wherein said high vertical viewing angle is in the range of20° to 70° to the horizontal.
 12. The seat of claim 11, wherein saidhigh vertical viewing angle is in the range of 25° to 55° to thehorizontal.